Essentially two types of laser are utilized in ophthalmology, namely, Ar/Kr gas discharge laser for coagulation which is driven by steady power in continuous-wave operation in the range of several watts as well as pulsed Nd-YAG-laser for microsurgery which is driven by pulsed energy in the mJ-range. Since both types of laser are each operated in only one operational mode, namely, continuous-wave driven or pulse driven, their use in ophthalmology leads to respective individual apparatus configurations which are more or less complex. Combination apparatus which are suitable for coagulation as well as for microsurgery can only be realized by combining the above-mentioned laser devices on an ophthalmologic apparatus such as a slit lamp and are technically complex and correspondingly expensive.